Thread: compiling a file

suppose there is a file test.java .
Aim is to compile this file and if compile is successful(no errors ) then run this file i.e java test.
problem is i need to do all this i.e compilation and run of 'test' from a java program only.
this java program must able to compile any file and then run that file.

Not sure if I understand what you are asking so I'll post a link to the intro tutorial (Trail: Getting Started (The Java™ Tutorials)), and if you want to do what I think lead you towards calling Runtime.getRuntime().exec(); to compile and run from your app (will be platform dependent though)

To clear the thing..
suppose there is a java program "runother".
now when you run this program this would ask for input filename.
and suppose the user input filename is "test".
now the "runother" should able to compile the "test" and then run the "test" if there is no error in compilation stage.

this should do what you are wanting:

String fileLocation;                                      // the folder the file is located
String file;                                                   // the name of the actual file (without any extensions
                                                                   // eg "hello" not "hello.java"
 
String[] commands = {"cmd", "cd" + fileLocation, "javac"+file+".java", "java"+file};
Runtime.getRuntime().exec(commands);

I think java has classes you can use to compile a program from a running java program.